Automatic rim rolling apparatus



Feb. 1, 1966 RUKAVlNA 3,232,453

AUTOMATIC RIM ROLLING APPARATUS Original Filed Aug. 20, 1962 2 Sheets-Sheet 2 i I 54 i I 5e r!) HEAT SUPPLY INVENTOR.

F k Ru/rav' a W )WMW ATT'YS United States Patent 3,232,453 Patented Feb. 1, 1966 3,232,453 AUTOMATIC RIM RGLLEN G APPARATUS Frank Ruhavina, Des Plaines, Ill., assignor to Illinois Tool Works, Inc, Chicago, 111., a corporation of Delaware Original application Aug. 20, 1962, Ser. No. 218,075, new

.latent No. 3,192,565, dated July 6, H65. Divided and this application Dec. 23, 1964, Ser. No. 420,546

4 Claims. (Cl. 214-45) This is a division of patent application Serial No. 218,075, filed August 20, 1962, now Patent No. 3,192,565.

This invention relates to a method and apparatus for curling beads and more particularly is concerned with apparatus for automatically curling beads on extremely thin-walled plastic cups and the like which are received from an intermittent source.

Thin wall plastic cups and containers have many advantages over conventional paper cups or containers in that they are moisture-proof and extremely light in weight while of adequate strength. When the cup blanks are cut rom a plastic sheet during formation thereof, a certain amount of flash is left by the molding apparatus along the cut edge and this presents a sharp edge often knife-like in character. To guard against injury to fingers and to the mouth and to further strengthen the cup or other container, the edge of the cup is folded over to provide a rolled lip with the previously mentioned cut edge positioned in an inaccessible position next to the cup body.

While this invention will be discussed relative to a plastic cup for association with vending machines, it is to be especially noted that other types of plastic conta ners such as ice cream containers, cottage cheese containers, and other packaging containers areexpressly contemplated.

The plastic cups are molded in a machine at a rate which often exceeds 300 per minute and the characteristic of the molding machine is such that the cups are delivered in batches of 12, 16, or 25. For fast removal of the batches of cups in the molding machine, it has been found advantageous to blow the cups, which are extremely light in weight, from the molding area to an orienting station which orients all of the cups in a particular position. A preferred type of orienting apparatus is of the type set forth in the co-pending application (Serial No. 39,009 filed June 27, 1960, now Patent No. 3,086,822) and assigned to the same assignee. From the orienting station, the cups are transported by automatic means to a rim rolling station. The rim rolling apparatus includes a plurality of axially aligned rollers circumferentially spaced around a central aperture, each roller having a spiral groove which engages the rim of the molded cup and distorts the rim to its final shape; at least one of the rollers is heated.

It is most important to have an accumulator station disposed a short distance vertically above therim rolling apparatus to accumulate a plurality of cups as rece ved from the orienting station so that a stack of cups will be presented to the rim rolling apparatus. This is important since when the cups are in stacked position the individual cups within the stacks are prevented from becoming cocked, and cross threading engagement of the rims of an individual cup with the rollers in the rim rolling apparatus is prevented.

It is a general object of this invention to provide a method and apparatus for automatically rolling rims on thin plastic containers in a fast, repetitive, trouble-free manner at high operating speeds.

It is another object of this invention to provide a method and apparatus for receiving lightwe ght plastic containers from an intermittent source, accumulating a predetermined number of containers at a station, and then feeding the containers so accumulated to the rim rolling apparatus.

A still further object of this invention is to provide an accumulator means which is work dependent rather than time dependent, which is simple in operation, easy to construct, and well adapted for the purposes for which it is designed.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will be best understood by the following description of the specific embodiment when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic view of apparatus for practicing the invention, the flow of cups through the apparatus being from left to right;

FIG. 2 is an enlarged view, partially in section, showing the accumulator station of the apparatus;

FlG. 3 is a sectional view along lines 33 of FIG. 2;

FIG. 4 is a sectional view along lines 4-4 of FIG. 2;

FIG. 5 is a sectional view of the apparatus including the accumulator and the rim rolling station;

FIG. 6A is a fragmentary view of the rim portion of a cup as it is received from a molding machine prior to the rolling of the rim thereon; and

FIG. 6B is a fragmentary sectional view of the rim portion of a cup after the rim has been rolled thereon by the apparatus shown in FIG. 5.

Cups 8 are received from a molding machine (not shown) and are oriented and have the rims rolled thereon by an apparatus 10 in an automatic manner as about to be discussed. More particularly, the apparatus 10 comprises an orienting station 12 of the type set forth in the aforementioned patent numbered 3,086,822, a transporting means 14 including a blower means 16 and a tube means 13 which receives the output from the orienting station 12. The tube means 18 leads to the accumulator sta tion 22, it being important to note that the tube means 18 has a vertical portion 20 immediately above the accumulator station 22. From the accumulator station 22, the cups are automatically passed in an accumulated batch to the rim rolling station 24 from whence they are automatically delivered with the rims rolled thereon to the output 26.

It will be appreciated that the cups 3 have their largest diameter adjacent the area where the head is to be rolled thereon, i.e., at the mouth of the container and that the side walls thereof taper inwardly. The cups have a configuration which permits close nesting, having tapered side walls with a plurality of gripping rings therein to reduce heat transfer to the fingers of the user, and have a stacking ring area adjacent the bottom of the cup as best depicted in FIG. 2. The weight of the cups is usually in the neighborhood of 1 to 10 grams depending upon the final usage and requirements of the user. It will also be noted that the diameter of the mouth of the cup is less than the axial height thereof and that the inside of the tube 18, particularly at portion 20, has an inside diameter closely approximating the diameter of the mouth area of the cup 8. It will also be appreciated due to the taperedside walls, that an individual cup may be cocked relative to the side walls of the tube. This is particularly undesirable as shall become apparent hereinafter.

When the cups 8 leave station 12, they are preferably oriented with the mouth portion thereof leading the bottom wall portion. When the cups 8 proceed through the tube 18 and reach the accumulator station 22 under the positive pressure imparted by the blower means 16 which blOWs air through the tube 18, the lead cup will engage a movable abutment means at the accumulator station 22 as will be now described.

The accumulator station 22 comprises a pair of slots 28 and 3% which are formed in portion 20 and aligned with the vertical axis thereof, the two portions 20 being preferably disposed in a single diametrical plane. The slot 28 is longer than the slot 34) for purposes hereinafter appearing. The movable abutment means 32 is in the form of a pivotal lever means having a counterbalance portion 34 and a narrower cup engaging portion 36, the latter extending through the slots 28 and 30 as shown in FIGS. 2 and 4. The narrower portion 36 has a through bore 38 for receipt of the pivot pin 40 which is mounted to a pair of spaced bracket means 42 and 44 adjacent to the upper end of the slot 28. The lever means 32 may be made of nylon or any other suitable material, it being referred that the material is the type which is relatively rigid and has a relatively smooth surface. The disposition of the through bore 38 for mounting the pivot pin is such that the lever will assume an at-rest position in engagement with the top of slots 28 and 3t), and the end of the lever means 32 extending through the slot 30 is of such length that it may be pivoted so it can completely clear both slots to take a vertically aligned position to tube portion 20 such as shown in FIG. 5. The exact amount of material by which portion 34 exceeds the amount of material 36 may be varied to suit depending upon the number of cups desired to be accumulated. Further, additional counterweights may be hung if desired on portion 34 as is apparent. In cups of the type and size shown in FIG. 2, it has been found in actual practice that it is desirable to accumulate at least four or five cups in stacked nested relation as shown in FIG. 5, the accumulated weight thereof being sufficient to cause the lever to pivot to the position shown in FIG. 5. A stack of five cups gives sufiicient axial dimension to the plurality of cups so that the bottom-most cup will not become cocked relative to the grooved rollers in the rim rolling apparatus. As will be apparent, the lever means is work dependent rather than time dependent. In other words, it is the weight of the accumulated cups themselves which causes the lever to move so as to clear the tube to allow the cups to drop on down for entry into the rim rolling apparatus. The speed of the rim rolling apparatus is such that if a cup should come through the tube while the lever is starting to return to the position shown in FIG. 2, the cup will become centered on a cup which has not yet reached the entering threads on the rim rolling apparatus. In other words, there is sufiicient height between the bottom of the uppermost cup in a stack which has passed the lever so that as the lever starts to clear same as versus the speed of the rim rolling apparatus such that if a cup comes down while the lever is returning and causes it to again swing out to the position shown in FIG. 5, the cup will not hit the entering thread but will hit the cups that are still awaiting entry into the rim rolling apparatus. Cooking is prevented because the relatively greater dimension of the mouth of the cup relative to the narrower dimension of the bottom causes a late coming cup to center itself on the next cup so that it will not in turn be cocked when it reaches the rim rolling apparatus.

The rim rolling station 24 is adapted to roll the rim area 48 of the cup 8 having the rather sharp edge 50 which is spaced from the side wall 54 on the cup 8. This edge 50 is turned back toward the mouth portion 52 to provide the rolled head 56 shown in FIG. 6B. The rim rolling apparatus essentially comprises a plurality of axially aligned rollers such as 58 and 6% (it being preferable that there be at least a total of-four rollers similar to rollers 58 and Gil) with at least one roller being heated as shown semidiagrammatically at 68. The individual rollers 58 and 60 are adapted to be rotated about their respective axis by suitabledrive means shown semidiagrammatically with the reference numeral 66. Each roller has a spiral groove such as shown at 62, the width of which varies progressively along the axial extent so that at 64 it is smaller in size to cause the rim to be rolled into the closed formation as shown in FIG. 6B. The disposition of the grooves 62 near the top of the roller is such as to cause a slight denesting of adjacent containers in the stack received from the accumulator means so that each cup is individually free of the next adjacent cup during the rim rolling operation. It is important to note that the grooves 62 and 64 are such as to cause only axial forces on portions 59 and 52 of the cup rather than supplying any radially inward component of force. This is important because essentially there is nothing to provide a reaction force to the relatively open mouth of the container in area 48 during the rim rolling operation and if the forces are not all substantially axial on portions 50 and 52, the net result is to cause the container to go through the rim rolling apparatus without any change in form. The heating of at least one and preferably all of the rollers serves to cause the plastic material to become moldable to aid in deformation thereof so as to retain its finally deformed shape 56. It will be noted that the narrowing of the width of the grooves 62 at 64 is such as to provide a camming action upon the rim portion 48 of the cup as it is received from the accumulator.

It is to be understood that the specific embodiment of the invention' as herein shown and described is for illustrative purposes only. Various changes in structure will no doubt occur to those skilled in the art and are to be understood as forming a part of this invention insofar as it follows in the spirit and the scope of the appended claims.

Iclaim:

1. An accumulator mechanism comprising hollow tube means adapted to transport oriented articles therealong and having at least a portion disposed in a substantially vertical plane, the substantially vertically extending portion of said tube means having first and second diametrically opposed slot means aligned with the axis thereof, portions of the tube means immediately above and longitudinally aligned with the upper end of each slot means being generally transversely aligned with each other, bracket means mounted on said tube means adjacent the upper end of said first slot means, and lever means made of self-lubricating material pivotally mounted on said bracket means outside the passageway of said tube means and below, but adjacent the upper ends of said slot means, said lever means having a first portion extendlng through said first and second slot means and a second heavier portion exterior of said first slot means, the first portion of said lever means being dimensioned to extend across said tube means and engage the portions thereof immediately adjacent to and longitudinally aligned with the upper ends of said slot means to provide a generally horizontally extending movable abutment in a normal at-rest position, said lever means remaining at said atrest position until the accumulation of a predetermined number of articles exceeds the weight of said second heavier portion whereupon said lever means pivots out of the way to release said articles, the axial length of each slot means being sufficient to permit the movement of said lever means in the aforesaid manner.

2. The apparatus set forth in claim 1 wherein said bracket means comprises a pair of spaced, generally opposed plate-like supports each mounted to said tube means adjacent the upper end of said first slot means for accepting said lever means therebetween, said plate-like supports and said lever means each having an aperture adapted to be aligned with one another for receiving a lever pivoting and mounting pin.

3. The apparatus set forth in claim 1 wherein said first and second portions of said lever means are integrally joined to one another.

4. The apparatus set forth in claim 1 wherein the diameter of at least a portion of each of said articles closely approximates the internal dimension of said tube means in the substantially vertieally extending portion thereof, said first slot means having an axial dimension at least as great as the internal dimension of said tube means to permit movement of the first portion of said lever means outside of said tube means for passage of said articles.

References Cited by the Examiner UNITED STATES PATENTS Yaggy l9428 Olvis 194-403 X Young 1933l X Jagenberg 9393 X Glaza 193-18 Moeller 193-32 X m GERALD M. FORLENZA, Primary Examiner.

MORRIS TEMIN, Examiner. 

1. AN ACCUMULATOR MECHANISM COMPRISING HOLLOW TUBE MEANS ADAPTED TO TRANSPORT ORIENTED ARTICLES THEREALONG AND HAVING AT LEAST A PORTION DISPOSED IN A SUBSTANTIALLY VERTICAL PLANE, THE SUBSTANTIALLY VERTICALLY EXTENDING PORTION OF SAID TUBE MEANS HAVING FIRST AND SECOND DIAMETRICALLY OPPOSED SLOT MEANS ALIGNED WITH THE AXIS THEREOF, PORTIONS OF THE TUBE MEANS IMMEDIATELY ABOVE AND LONGITUDINALLY ALIGNED WITH THE UPPER END OF EACH SLOT MEANS BEING GENERALLY TRANSVERSELY ALIGNED WITH EACH OTHER, BRACKET MEANS MOUNTED ON SAID TUBE MEANS ADJACENT THE UPPER END OF SAID FIRST SLOT MEANS, AND LEVER MEANS MADE OF SELF-LUBRICATING MATERIAL PIVOTALLY MOUNTED ON SAID BRACKET MEANS OUTSIDE THE PASSAGEWAY OF SAID TUBE MEANS AND BELOW, BUT ADJACENT THE UPPER ENDS OF SAID SLOT MEANS, SAID LEVER MEANS HAVING A FIRST PORTION EXTENDING THROUGH SAID FIRST AND SECOND SLOT MEANS AND A SECOND HEAVIER PORTION EXTERIOR OF SAID FIRST SLOT MEANS, THE FIRST PORTION OF SAID LEVER MEANS BEING DIMENSIONED TO EXTEND ACROSS SAID TUBE MEANS AND ENGAGE THE PORTIONS THEREOF IMMEDIATELY ADJACENT TO AND LONGITUDINALLY ALIGNED WITH THE UPPER ENDS OF SAID SLOT MEANS TO PROVIDE A GENERALLY HORIZONTALLY EXTENDING MOVABLE ABUTMENT IN A NORMAL AT-REST POSITION, SAID LEVER MEANS REMAINING AT SAID ATREST POSITION UNTIL THE ACCUMULATION OF A PREDETERMINED NUMBER OF ARTICLES EXCEEDS THE WEIGHT OF SAID SECOND HEAVIER PORTION WHEREUPON SAID LEVER MEANS PIVOTS OUT OF THE WAY TO RELEASE SAID ARTICLES, THE AXIAL LENGTH OF EACH SLOT MEANS BEING SUFFICIENT TO PERMIT THE MOVEMENT OF SAID LEVER MEANS IN THE AFORESAID MANNER. 